Direction change apparatus for sheet conveyance systems

ABSTRACT

Apparatus for changing the flow direction of a spaced series of planar sheets relative to the orientation of said sheets and subsequently closing the space therebetween under continuous flow conditions of said sheet series.

United States iatent n 1 Glanz et al.

[451 Apr. 10, 1973 DIRECTION CHANGE APPARATUS FOR SHEET CONVEYANCESYSTEMS Inventors: Ronald P. Glanz; Clifford D. Shelor,

both of Covington, Va.

Assignee: Westvaco Corporation, New York,

Filed: July 22, 1971 Appl. No.: 165,85 1

US. Cl. ..83/79, 83/96, 83/112, 83/156, 83/158, 83/358, 83/423, 83/4253,198/82 Int. Cl. ..B65h 35/02 Field of Search ..83/79, 96, 112, 156,

[56] References Cited UNITED STATES PATENTS 3,224,307 12/1965 Kiuker..83/112 X 3,486,405 12/1969 Schubert ..83/158 X Primary Examiner-FrankT. Yost Att0rneyRichard L. Schmalz et a1.

[ 5 7 ABSTRACT Apparatus for changing the flow direction of a spacedseries of planar sheets relative to the orientation of said sheets andsubsequently closing the space therebetween under continuous flowconditions of said sheet series.

18 Claims, 5 Drawing Figures PATENTED APR 1 0 975 SHEET 1 [1F 3INVENTORS RONALD P GLANZ CLIFFORD D.SHELOR PATENTEU 3.726.168

sum 2 nr 3 33a 38 33b 3lb 310 .1 I

INVENTORS RONALD F? GLANZ CLIFFORD D. SHELOR PATENTEDAPR 1 019153.726.168

SHEET 3 OF 3 FIG. 5

IN VEIV mns RONALD P. GLANZ BYCLIFFORD D. SHELOR DIRECTION CHANGEAPPARATUS FOR SHEET CONVEYANCE SYSTEMS BACKGROUND OF THE INVENTION 1.Field of the Invention This invention relates to a conveyance system fora continuing series of sheets or thin strips of planar material and thereorientation of same relative to the flow direction.

2. Description of the Prior Art In the continuous production of cellularcores for laminated structural panels from solid or corrugated sheetstock, long strips of relatively slender width are cut from large sheetsor a continuous web of supply stock. For the purpose of improvedmechanical properties, these strips are turned (collimated) whereby thesheet plane of individual strips is positioned perpendicular to the coreor panel face.

If the material flow is unidirectional, however, from cutting station tothe collimating station, the linear panel production rate is limited bythe rate at which one or very few cutting tools, e.g. saws, can traversethe supply stock width. The U. S. Pat. No. 3,017,971 to Christiandiscloses such a machine wherein the conveyance line must be stoppedwhile the saw blade, usually mounted on a linearly reciprocable spindle,makes a cutting pass across the stationary conveyance line.

In the present invention, supply stock is hopper fed to the saws asprecut panels. Instead of traversing stationary stock with a movablecutting tool, this invention takes advantage of the fact that greaterpower and cutting plane stability may be delivered to a stationary toolaxis. Accordingly, correctly oriented, precut panels are moved past astationary, gang saw cutting tool rendering the entire panel to stripsin a single pass. However, material flow direction of the strips at thispoint is parallel with the cutting planes. To collimate these stripsinto laminated cellular cores, it is necessary that the strip flowdirection be perpendicular to the cutting planes thereof. Moreover, saidstrips must be fed to the collimator in an uninterrupted, serial flowsequence. Another object of this invention, therefore, is to cut eachpanel of a flowing series into a row of strips having laterally adjacentlongitudinal edges and sequentially collimating each row into a singlecontinuous column of strips with adjacent longitudinal edges.

Since some operations in the flow sequence require greater timeintervals than others, it is a further object of this invention toautomatically coordinate events at each operating station to yield thegreatest possible flow rate.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 2 is a plan schematic of thesawing and direction changing operations of the present invention;

FIG. 3 is an elevational schematic of the reoriented strip supply lineand collimating operation taken at out line IlI--lll of FIG. 1;

FIG. 4 is a plan schematic of the reoriented supply and collimatingoperations of FIG. 3;

FIG. 5 is a circuitry schematic of the present invention showing theapparatus and logic for controlling material flow from a panel hopper toa strip collimator.

DESCRIPTION OF THE PREFERRED EMBODIMENT Relative to the elevation ofFIG. 1, there is shown, within the area bounded by the dashed line 1, acorrugated web fabricator for solid sheet materials such as kraft paperor aluminum foil. Corrugated panels 73 of uniform size produced by thecorrugated fabricator 1 are deposited in the feed hopper 20 of a stripcutting operation 2 to be cut into strips 74. From the cutting operation2, the strips 74 are deposited at a direction change station 30 of acollimator feed conveyor 3. From the conveyor 3, the strips 74 are fedas a continuous line into a collimating and core panel fabricationoperation 4 to be reoriented and structurally bound together as anintegral core continuum 77.

The corrugated web operation 1 may be performed independently in timeand space of the sawing and reoriented conveyance system of theinvention but is most efiiciently executed in contiguous proximitythereof.

Starting with the roll 10a of solid material sheet stock, kraft paperfor example, web a is passed over the corrugating roll 11a and throughthe nip 12 formed by the meshing involutes of rolls 11a and 11b.Emerging from the nip 12, the corrugated web 70b is held against theinvoluted surface of roll 11b by retaining fingers l3. Adhesive such asvegetable glue is continuously applied to the involute crest lines ofone web face by applicator roll 14a. An uncorrugated web 710 is reeledfrom roll 10b, passed over an idler roll and around nip roll 15a intopressured contact with the glue lines on corrugated web 70b to form asingle faced corrugated web 72a. Other idler rolls direct the web 72ainto the nip of glue applicator 14b so adhesive may be applied to thecorrugation crest lines on the bottom face of web 7012. Reel suppliesthe uncorrugated web 71b around nip roll 15b into pressured contactwith. said bottom crest glue lines to secure the remaining face of adouble faced corrugated web 72b. Thereafter the web is drawn over aheater platen 16 by a pulling section comprising traction belts 17a and17b driven between roller platens l8. Rotary knife 19 cuts thedouble-faced corrugated web 72b into corrugated panels 73 of uniformlength and width which may be gravity dropped into feed hopper 20 of thestrip cutting operation 2.

The vertical dimensional relationship between the bottom edge of hopperside 20a and the reciprocating lug 21a of the slider-crank feedmechanism 21 is such as to allow only one panel 73 to be sheared frombeneath the hopper stack in a single cycle of the crank 21b.

Advancement of a panel 73 by the lug 21a engages the panel with cuttingedges of gang saw 22. The spacing W between each circular blade 22a issuch as to divide the panel 73 into a number of long, narrow, thinstrips 74, each of uniform width W, length L and thickness T. Although aserrated circular saw has been found for the present to be the mostsatisfactory cutting device for kraft paper, one attendant disadvantageof the device is the immense production of saw dust necessitating avacuum removal system 22b. Another disadvantage of the circular saw ismaterial wastage from the saw kerf. Depending on the properties of thesolid sheet stock 70 and 71 and the related economics, other cuttingtechniques such as rotary shears, band saws, hydraulic jets or lasersmay be utilized since the cutting function is to completely separateeach strip 74 from the one next adjacent.

It should also be noted that orientation of the panel 73 relative to thecutting planes of saw 22 is important to achieve maximum productstrength. For corrugated panels from the aforedescribed fabricatingoperation 1, the cutting planes should be perpendicular to thecorrugation flute axes i.e., the major compressive strength direction ofpanels 73.

Since the stroke of slider-crank mechanism 21 is only sufficient tostart the panel 73 through the saw 22, nip rolls 23 are employed totractionally complete the panel cut pass. Since it is not desirable tointerrupt the continuity of the panel cut pass, nip rolls 23 rotateconstantly to complete all panel cuts started by the slider crank 21.

From the nip of rolls 23, a strip group 75 comprising strips 74respective to a single panel 73 is deposited on a continuously movingbelt conveyor 24 and restrained by weight rolls 24a to the same relativeorientation as cut. However, selective deployment of the retractablefence 25 by electric or fluid powered linear actuator 25a operates tomake the conveyor 24 an effective holding station 26. Fence 25 obstructsthe progress of group 75 as belt 24 slips thereunder.

When conditions are correct for receipt of the strip group 75 by one ofthe endless tensile conveyance lines 31a or 31b at the direction changestation 30, the fence 25 is lifted by a functioning of the actuator 25awhereupon the belt conveyor 24 is allowed to advance the group 75 intothe nip of constantly rotating discharge rolls 27.

Allowing sufficient time to complete the transfer of strip group 75 fromthe holding station 26 to the direction change station 30, lugs 32a ofthe inside running tensile conveyor 31a engage the outermostlongitudinal edge of the outermost strip 75b to advance the strip group75 along the sliding surface 34.

Tensile conveyors 31a and 31b, which may be chains, belts, ropes, etc.running on overhead sprockets or sheaves are each driven independentlythrough respective variable speed force limiting devices such as torquelimiters 35a and 35b. When the control logic explained hereafterreleases either of the conveyors 31a or 31b to advance a strip group 75along the flow direction of feed conveyor 3, the conveyor does so withthe greatest permissible speed consistent with maintaining the order andalignment of all strips 74 within the group. This speed should besignificantly greater than the fastest rate capacity of collimator 4.Accordingly, the leading strip 75a of the group 75 propelled by lugs 32awill overtake the trailing strip 75b of the preceding group propelled bylugs 32b whereupon the speed will be governed by the prevailing rate ofthe collimator. Since it is highly desirable to advance the series ofstrips 76 into the collimator 4 in longitudinal edge-to-edge abutmentbetween respective strips, it is necessary to maintain a constant, lightpushing force upon the trailing strip of the series by the respectivelugs. These several criteria of variable speed and constant force may beperformed by a base mounted, input clutch brake module specified as EM-l80-20 -30 B in Master Catalog No. 67 of the Warner Electric Brake andClutch Co., Beloit, Wisconsin.

After the strip series on the collimator feed line 3 passes under thevertical restraining tines 36, a planar divergence is provided betweenthe respective paths of lugs 32 and 33 and the strip feed plane 34 toallow the withdrawal of a lug set.

In the embodiment shown, each tensile conveyance line 31a and 31b isprovided with two sets of peripherially opposite lugs: 32a and 33a; and32b and 33b, respectively. Therefore, in each line 31a and 31b, one pairof lugs, 33a for example, is advancing toward the direction changestation 30 while the other set, 32a, is proceeding away with a stripgroup 75.

For the purpose of fully automatic coordination of strip cuttingoperation 2 with the direction changing feed conveyor 3, the controllogic and apparatus of FIG. 5 may be utilized. The downstream boundaryof change station 30 is defined by a planar path 38 wherein is disposeda normally closed limit switch 80. Obviously, any of the numerousdevices available for sensing the presence or absence of the stripmaterial such as photoelectric and sonic proximity switches may be usedin lieu of switch 80. It is only important that the passage of a stripgroup be signified by a distinct electrical signal.

Opening of circuit 90 is occasioned by depression of switch trigger awhen the lead strip 75a of a group passes thereover. The electricaleffect of opening circuit 90 is to discharge circuit 91 therebyresetting time delay relay and the single revolution clutch 88 in thedrive train of slider-crank feed mechanism 21.

When the trailing strip 75b of a strip group completes passage overswitch trigger 80a, clearance of change station 30 is signaled by theswitch 80 closure of circuit 90. Energy from source G is simultaneouslytransmitted to circuits 91 and 92.

The bias of G present on the input of timing relay 85 in circuit 91immediately initiates an output conductance to energize singlerevolution clutch 88 to start one corrugated panel 73 through the saws22. The output of relay 85 is limited, however, for a time period ATless than one complete cycle of crank 21. Without the bias of circuit 91on the clutch 88 to sustain engagement, disengagement thereof occursmechanically after one revolution. A single revolution clutch of thetype described is available from Precision Specialities, Inc., DelseaDrive, Pitman, New Jersey and specified by their November, 1968, DataSheet A-l6 as an Incremental Rotation Control Package Model CB-6.

If another strip group 75 is waiting at holding station 26, trigger 82awill depress the bus bar of switch 82 into engagement with contacts 82bto complete circuit 92 with the winding of electrical actuator 25a forgate 25. Since the belt conveyor 24 is continuously operating beneaththe strip group, movement onto the direction change station 30 thereofbegins immediately upon lifting the gate 25. Discharge rolls 27 are alsocontinuously operating, thereby assuring the complete delivery of group75 to change station 30 even after the trailing end of the group passestrigger 82a to open contacts 82b of circuit 92 thereby closing gate 25.

The absence of material a holding station 26 prompts the closure ofcontacts 820 to complete the circuit 93 with energy source 0 From thatmoment, time delay relay 86 starts counting down to AT a function of thetime required for the foregoing strip group 75 to be completelydeposited and settled at change station 30. At the expiration of ATrelay 86 transmits a single pulse to distributor switch winding 83a andcuts off. The single pulse from relay 86 is sufficient to cycle thelinear pawl 83b against one spur of wheel 83c thereby indexing cam 83afrom the preceding high surface position 83c to the next low position83f. Cam follower 83g reciprocates between said cam highs and lows toalternate bus bar 83h between contacts 831 and 83j, completing circuits95 and 94 with energy source G respectively and exclusively.

Circuit 95 includes a control complement for tensile conveyor 31bidentical to that for 31a described below. The primary function ofdistributor switch 83 is, therefore, to select which of the twoindependently driven tensile conveyors shall carry the next strip group75.

When distributor switch cam 83d is indexed to a high position 832relative to the follower 83g, bus bar 83h closes contacts 83j in circuit94 with energy source 0;. The consequent input bias on time delay relay87 initiates immediate conductance from the output thereof to thewinding 84a of holding relay 84. Said relay output is limited, however,for the discrete period of time AT, necessary to close and lock saidholding relay 84.

Actuation of winding 84a closes contacts 84b and 840 between energysource 0, and circuits 96 and 97. Circuit 97 conducts energy to electricclutch 89 in the drive train of tensile conveyor 31a. Circuit 97provides a continuing conduit of energy from source G, to winding 84a'tohold contacts 84b and Me closed after time period AT has expired andrelay 87 has ceased conducting.

The function of holding circuit 96 is to keep conveyor 31a drive trainengaged after switch 80 has called it into service. This condition mustbe sustained until the engaged lug set, 32a for example has released itscharge of strips to the belt conveyor 37. At this time, peripheriallyopposite lug 33a approaches the actuating finger 81a of interruptingswitch 81. When opened, switch 81 interrupts the holding circuit 96 forholding relay 84 thereby interrupting the power circuit 97 to clutch 89and stopping tensile conveyor 31a.

Without the interrupting switch 81, once a tensile conveyor was startedthere would be no coordination between the placement of a strip group 75in the direction change station 30 and the location of a lug. anualsurveillance would be required to prevent interferences.

Belt conveyor 37 propels the strip line 76 into the collimator 40 afterthe withdrawal of tensile conveyor lugs therefrom. Additional thrust toeach strip 74 is provided from dogs 39a and 39b which are compliant,

centrifugal extensions of belt sheave 39. Dogs 39:; and 6 39b provide aconcentrated, positive loading force for collimator breech 41 to assurethat a single strip 74 advances completely into the breech 41 during thereciprocatory half-cycle interim that the trip-hammer 42 is withdrawntherefrom.

Although not critical, the line of belt conveyor 37 is a convenientlocation for one or more adhesive applicators Wit to dispense adhesiveto at least one face of strips 74.

The actual collimating function is performed as an individual strip 74is thrust edge first into the breech 41 against the surface of table 44with the corrugation flute axes perpendicular thereto. Trip-hammer 42,cyclically driven by eccentric 43, strikes one face of the strip 74 topush it clear of the breech M; into intimate, face-to-face contact withthe preceding strip; and to advance the entire, collimated series ofstrips along the table surface 44.

Although a preferred circuitry apparatus for the coordinated control ofsheet material from the hopper 20 to a discharge receptacle such as beltconveyor 37 has been disclosed herein, it should be understood thatnumerous functional equivalents utilizing semiconducting devices may besubstituted therefor. The significance of the preferred circuit is toillustrate the coordinating logic whereby the removal of a strip group75 from the direction change station 30 first starts a new panel 73 intothe saws 22. While the sawing operation proceeds, the slowest of theseries, any group 75 present at the holding station 26 is conveyed ontothe change station 30. Depending on the exact locations of switches 81and 82, the time required for group 75 to settle onto change station 30and the startup speed of the tensile conveyors, the clutch 89 is engagedat the moment required to allow lugs 33a to engage the strip group 75immediately after settling.

With proper adjustment of minimum requisite time delay cycles, anapparatus constructed according to the present invention should conveyapproximately 1,000, three-eighths in. strips per minute from 60 60 inchpanels of double face, A/A flute, 42 pound kraft paper corrugated boardstock.

While the primary objective of this invention has been to cut andfacilitate the orderly flow of long, norrow strips of thin sheetmaterial, it should be recognized that the invention will expedite theorderly flow of uncut panels in those circumstances where panelreorientation relative to flow direction is necessary between twosuccessive operations.

We claim as our invention:

1. Material transfer apparatus for sustaining a constant relativeorientation between each of a flowing series of planar sheets andchanging the flow direction thereof, said apparatus comprising:

first conveyance means extending along a first direction to deliver aspaced planar series of parallel planar sheets from a source to adirection change station with a predetermined relative orientation andholding station therebetween;

second conveyance means extending along a second direction substantiallytransverse to said first direction to serially deliver said sheets fromsaid direction change station to a receptacle without said planarspacing and without changing said relative orientation; and

control means for regulating the flow of sheets from said-source to saidfirst conveyance means, from said holding station to said change stationand the engagement of said sheets by said second conveyance means atsaid change station.

2. Apparatus as described by claim 1 wherein said source of parallelplanar sheets comprises cutting means for cutting large planar sheetsinto a plurality of smaller planar sheets along substantially equallyspaced parallel cutting planes extending coplanar with said firstdirection.

3. Apparatus as described by claim 1 wherein said holding stationcomprises means to stop movement of a particular sheet before deliveryto said change station without stopping movement of sheets followingthereafter.

4. Apparatus as described by claim 1 werein said second conveyance meanscomprises a plurality of conveyor elements, each element having mutuallyindependent driving means that are engagably dependent on said controlmeans.

5. Apparatus as described by claim 3 wherein said holding stationcomprises removable, sheet movement obstructing means.

6. Apparatus as described by claim 4 wherein said driving means eachdeliver a predetermined, relatively constant force over a speed rangeincluding stationary.

7. Apparatus as described by claim 6 wherein said control meanscomprises first sheet sensing means adjacent to and down stream of saiddirection change station, said sensing means transmitting a first signalto deposit a single sheet with said first conveyance means when thepassage of a sheet is sensed thereby.

8. Apparatus as described by claim 7 wherein said control means furthercomprises second sheet sensing means adjacent said holding stationwhereby said first signal is further transmitted to actuator means toremove said holding station obstruction means when the presence of asheet at said holding station is sensed by said second sensing means.

9. Apparatus as described by claim 8 wherein said second conveyancemeans comprises a plurality of conveyor elements, each element havingmutually independent driving means that are engagably dependent on saidcontrol means and operable to deliver a predetermined, relativelyconstant force over a speed range including stationary.

10. Apparatus as described by claim 9 wherein said second sensing meanstransmits a second signal to second conveyance element selector meanswhen a sheet passes from said holding station to engage said conveyanceelement with respective driving means.

11. Apparatus as described by claim 10 further comprising conveyanceelement stop control means respective to each of said elements, saidstop control means causing the disengagement of respective drive meansafter deposit of a sheet with said receptacle.

12. Apparatus for the continuous fabrication and supply of long narrowstrips from relatively thin panels of sheet material, said apparatuscomprising:

first and second material flow directions, each substantially transverseof the other;

cutting means for successively cutting first and second panels of sheetmaterial into a plurality of long, narrow strips along cutting planesparallel with said first flow direction;

first conveyance means for successively delivering said panels throughsaid cutting means;

second conveyance means for delivering strip groups respective to saidpanels emerging from said cutting means to a holding station and to aflow directional change station in the order and orientation as cut;third conveyance means for engaging sald first panel strip group, in theorientation as cut, at said change station and moving same along saidsecond flow direction;

fourth conveyance means for engaging said second panel strip group, inthe orientation as cut, at said change station and moving same along thesame path in said second flow direction as followed by said first panelstrip group; and,

first control means for stopping said second panel strip group movementat said holding station until said third conveyance means moves saidfirst panel strip group clear of said change station.

13. Apparatus as described by claim 12 further comprising second controlmeans for selectively stopping either of said third and fourthconveyance means until a respective panel strip group is completelydelivered to said change station.

14. Apparatus as described by claim 13 wherein said second material flowdirection path comprises a stationary surface for sliding said stripsand said third and fourth conveyance means comprise endless tensilemembers having lugs secured thereto for pushing said strips along saidsliding surface.

15. Apparatus as described by claim 13 further comprising independentdriving and force control means respective to each of said third andfourth conveyance means whereby the leading strip of said second panelstrip group may abutt but not otherwise disturb the trailing strip ofsaid first panel strip group along said second flow path.

16. Apparatus as described by claim 14 wherein said third and fourthconveyance means each comprise at least two sets of lugs whereby one setapproaches said change station while the other set delivers a respectivepanel strip group therefrom.

17. Apparatus as described by claim 12 wherein said first conveyancemeans function cyclically to deliver a single panel through said cuttingmeans per cycle, each being started by signal means responsive to theclearance of a preceeding panel strip group from said change station.

18. Apparatus as described by claim 17 wherein said signal means isemitted by said first control means.

0 t t i 1

1. Material transfer apparatus for sustaining a constant relativeorientation between each of a flowing series of planar sheets andchanging the flow direction thereof, said apparatus comprising: firstconveyance means extending along a first direction to deliver a spacedplanar series of parallel planar sheets from a source to a directionchange station with a predetermined relative orientation and holdingstation therebetween; second conveyance means extending along a seconddirection substantially transverse to said first direction to seriallydeliver said sheets from said direction change station to a receptaclewithout said planar spacing and without changing said relativeorientation; and control means for regulating the flow of sheets fromsaid source to said first conveyance means, from said holding station tosaid change station and the engagement of said sheets by said secondconveyance means at said change station.
 2. Apparatus as described byclaim 1 wherein said source of parallel planar sheets comprises cuttingmeans for cutting large planar sheets into a plurality of smaller planarsheets along substantially equally spaced parallel cutting planesextending coplanar with said first direction.
 3. Apparatus as describedby claim 1 wherein said holding station comprises means to stop movementof a particular sheet before delivery to said change station withoutstopping movement of sheets following thereafter.
 4. Apparatus asdescribed by claim 1 werein said second conveyance means comprises aplurality of conveyor elements, each element having mutually independentdriving means that are engagably dependent on said control means. 5.Apparatus as described by claim 3 wherein said holding station comprisesremovable, sheet movement obstructing means.
 6. Apparatus as describedby claim 4 wherein said driving means each deliver a predetermined,relatively constant force over a speed range including stationary. 7.Apparatus as described by claim 6 wherein said control means comprisesfirst sheet sensing means adjacent to and down stream of said directionchange station, said sensing means transmitting a first signal todeposit a single sheet with said first conveyance means when the passageof a sheet is sensed thereby.
 8. Apparatus as described by claim 7wherein said control means further comprises second sheet sensing meansadjacent said holding station whereby said first signal is furthertransmitted to actuator means to remove said holding station obstructionmeans when the presence of a sheet at said holding station is sensed bysaid second sensing means.
 9. Apparatus as described by claim 8 whereinsaid second conveyance means comprises a plurality of conveyor elements,each element having mutually independent driving means that areengagably dependent on said control means and operable to deliver apredetermined, relatively constant force over a speed range includingstationary.
 10. Apparatus as described by claim 9 wherein said secondsensing means transmits a second signal to second conveyance elementselector means when a sheet passes from said holding station to engagesaid conveyance element with respective driving means.
 11. Apparatus asdescribed by claim 10 further comprising conveyance element stop controlmeans respective to each of said elements, said stop control meanscausing the disengagement of respective drive means after deposit of asheet with said receptacle.
 12. Apparatus for the continuous fabricationand supply of long narrow strips from relatively thin panels of sheetmaterial, said apparatus comprising: first and second material flowdirections, each substantially transverse of the other; cutting meansfor successively cutting first and second panels of sheet material intoa plurality of long, narrow strips along cutting planes parallel withsaid first flow direction; first conveyance means for successivelydelivering said panels through said cutting means; second conveyancemeans for delivering strip groups respective to said panels emergingfrom said cutting means to a holding station and to a flow directionalchange station in the order and orientation as cut; third conveyancemeans for engaging said first panel strip group, in the orientation ascut, at said change station and moving same along said second flowdirection; fourth conveyance means for engaging said second panel stripgroup, in the orientation as cut, at said change station and moving samealong the same path in said second flow direction as followed by saidfirst panel strip group; and, first control means for stopping saidsecond panel strip group movement at said holding station until saidthird conveyance means moves said first panel strip group clear of saidchange station.
 13. Apparatus as described by claim 12 furthercomprising second control means for selectively stopping either of saidthird and fourth conveyance means until a respective panel strip groupis completely delivered to said change station.
 14. Apparatus asdescribed by claim 13 wherein said second material flow direction pathcomprises a stationary surface for sliding said strips and said thirdand fourth conveyance means comprise endless tensile members having lugssecured thereto for pushing said strips along said sliding surface. 15.Apparatus as described by claim 13 further comprising independentdriving and force control means respective to each of said third andfourth conveyance means whereby the leading strip of said second panelstrip group may abutt but not otherwise disturb the trailing strip ofsaid first panel strip group along said second flow path.
 16. Apparatusas described by claim 14 wherein said third and fourth conveyance meanseach comprise at least two sets of lugs whereby one set approaches saidchange station while the other set delivers a respective panel stripgroup therefrom.
 17. Apparatus as described by claim 12 wherein saidfirst conveyance means function cyclically to deliver a single panelthrough said cutting means per cycle, each being started by signal meansresponsive to the clearance of a preceeding panel strip group from saidchange station.
 18. Apparatus as described by claim 17 wherein saidsignal means is emitted by said first control means.